1. Field of the Invention
The invention relates generally to the field of fingerprint scanner technology and, more particularly, to counting ridges in a captured fingerprint image frame.
2. Background Art
Biometrics are a group of technologies that provide a high level of security. Fingerprint capture and recognition is an important biometric technology. Law enforcement, banking, voting, and other industries increasingly rely upon fingerprints as a biometric to recognize or verify identity. See, Biometrics Explained, v. 2.0, G. Roethenbaugh, International Computer Society Assn. Carlisle, Pa. 1998, pages 1-34 (incorporated herein by reference in its entirety).
Fingerprint scanners having cameras are available that capture an image of a fingerprint. Typically, to capture a fingerprint image electronically with a fingerprint scanner, a light source is directed towards a fingerprint capture surface that reflects light from the light source towards a camera. The fingerprint capture surface is generally glass. Contact between the surface of a finger and the fingerprint capture surface causes the reflected light to be representative of the fingerprint of the particular finger placed against the fingerprint capture surface. This reflected light is then captured by camera. The fingerprint scanner may have processing that produces a signal representative of a captured fingerprint image from the reflected light.
The quality of contact between a finger and the fingerprint capture surface plays a large role in the intensity of the reflected light. A very dry skin surface on a clean fingerprint capture surface may result in a low intensity level of reflected light. On the other hand, an oily skin surface and/or a less-clean fingerprint capture surface may result in a high level of reflected light. Additional factors, such as the location of the finger, the pressure applied to press the finger to the platen, and the ambient environment may affect whether an acceptable quality fingerprint image is captured.
As a result of the above variations, a fingerprint scanner system and method that captures an acceptable fingerprint image is needed. Moreover, a system and method for determining the quality of a captured fingerprint image is desired.